American Journal of Botany最新文献

{"title":"Genetically correlated leaf tensile and morphological traits are driven by growing season length in a widespread perennial grass","authors":"P. Camilla Durant,&nbsp;Amit Bhasin,&nbsp;Thomas E. Juenger,&nbsp;Robert W. Heckman","doi":"10.1002/ajb2.16349","DOIUrl":"10.1002/ajb2.16349","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Leaf tensile resistance, a leaf's ability to withstand pulling forces, is an important determinant of plant ecological strategies. One potential driver of leaf tensile resistance is growing season length. When growing seasons are long, strong leaves, which often require more time and resources to construct than weak leaves, may be more advantageous than when growing seasons are short. Growing season length and other ecological conditions may also impact the morphological traits that underlie leaf tensile resistance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>To understand variation in leaf tensile resistance, we measured size-dependent leaf strength and size-independent leaf toughness in diverse genotypes of the widespread perennial grass <i>Panicum virgatum</i> (switchgrass) in a common garden. We then used quantitative genetic approaches to estimate the heritability of leaf tensile resistance and whether there were genetic correlations between leaf tensile resistance and other morphological traits.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Leaf tensile resistance was positively associated with aboveground biomass (a proxy for fitness). Moreover, both measures of leaf tensile resistance exhibited high heritability and were positively genetically correlated with leaf lamina thickness and leaf mass per area (LMA). Leaf tensile resistance also increased with the growing season length in the habitat of origin, and this effect was mediated by both LMA and leaf thickness.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Differences in growing season length may promote selection for different leaf lifespans and may explain existing variation in leaf tensile resistance in <i>P. virgatum</i>. In addition, the high heritability of leaf tensile resistance suggests that <i>P. virgatum</i> will be able to respond to climate change as growing seasons lengthen.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16349","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141085950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parallel patterns of genetic diversity and structure in circumboreal species of the Sphagnum capillifolium complex","authors":"Karn Imwattana,&nbsp;Blanka Aguero,&nbsp;Marta Nieto-Lugilde,&nbsp;Aaron Duffy,&nbsp;Juan Jaramillo-Chico,&nbsp;Kristian Hassel,&nbsp;Olga Afonina,&nbsp;Paul Lamkowski,&nbsp;A. Jonathan Shaw","doi":"10.1002/ajb2.16348","DOIUrl":"10.1002/ajb2.16348","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Shared geographical patterns of population genetic variation among related species is a powerful means to identify the historical events that drive diversification. The <i>Sphagnum capillifolium</i> complex is a group of closely related peat mosses within the <i>Sphagnum</i> subgenus <i>Acutifolia</i> and contains several circumboreal species whose ranges encompass both glaciated and unglaciated regions across the northern hemisphere. In this paper, we (1) inferred the phylogeny of subg. <i>Acutifolia</i> and (2) investigated patterns of population structure and genetic diversity among five circumboreal species within the <i>S. capillifolium</i> complex.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We generated RAD sequencing data from most species of the subg. <i>Acutifolia</i> and samples from across the distribution ranges of circumboreal species within the <i>S. capillifolium</i> complex.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We resolved at least 14 phylogenetic clusters within the <i>S. capillifolium</i> complex. Five circumboreal species show some common patterns: One population system comprises plants in eastern North America and Europe, and another comprises plants in the Pacific Northwest or around the Beringian and Arctic regions. Alaska appears to be a hotspot for genetic admixture, genetic diversity, and sometimes endemic subclades.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results support the hypothesis that populations of five circumboreal species within the <i>S. capillifolium</i> complex survived in multiple refugia during the last glacial maximum. Long-distance dispersal out of refugia, population bottlenecks, and possible adaptations to conditions unique to each refugium could have contributed to current geographic patterns. These results indicate the important role of historical events in shaping the complex population structure of plants with broad distribution ranges.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An adventurous journey toward and away from fern apomixis: Insights from genome size and spore abortion patterns","authors":"Libor Ekrt,&nbsp;Alžběta Férová,&nbsp;Petr Koutecký,&nbsp;Kateřina Vejvodová,&nbsp;Kiyotaka Hori,&nbsp;Ondřej Hornych","doi":"10.1002/ajb2.16332","DOIUrl":"10.1002/ajb2.16332","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Apomixis in ferns is relatively common and obligatory. Sterile hybrids may restore fertility via apomixis at a cost of long-term genetic stagnation. In this study, we outlined apomixis as a possible temporary phase leading to sexuality and analyzed factors relating to transitioning to and away from apomixis, such as unreduced and reduced spore formation in apomict and apo-sex hybrid ferns.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We analyzed the genome size of 15 fern species or hybrids (“taxa”) via flow cytometry. The number of reduced and unreduced gametophytes was established as a proxy for viable spore formation of either type. We also calculated the spore abortion ratio (sign of reduced spores) in several taxa, including the apo-sex hybrid <i>Dryopteris</i> × <i>critica</i> and its 16 apomictically formed offspring.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Four of 15 sampled taxa yielded offspring variable in genome size. Specifically, each variable taxon formed one viable reduced plant among 12–451 sampled gametophytes per taxon. Thus, haploid spore formation in the studied apomicts was very rare but possible. Spore abortion analyses indicated gradually decreasing abortion (haploid spore formation) over time. In <i>Dryopteris</i> × <i>critica</i>, abortion decreased from 93.8% to mean 89.5% in one generation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results support apomixis as a transitionary phase toward sexuality. Newly formed apomicts hybridize with sexual relatives and continue to form haploid spores early on. Thus, they may get the genomic content necessary for regular meiosis and restore sexuality. If the missing relative goes extinct, the lineage gets locked into apomixis as may be the case with the <i>Dryopteris affinis</i> complex.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140955798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in water economy traits in two Sphagnum species across their distribution boundaries","authors":"Charles Campbell,&nbsp;Gustaf Granath,&nbsp;Håkan Rydin","doi":"10.1002/ajb2.16347","DOIUrl":"10.1002/ajb2.16347","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>We assessed changes in traits associated with water economy across climatic gradients in the ecologically similar peat mosses <i>Sphagnum cuspidatum</i> and <i>Sphagnum lindbergii</i>. These species have parapatric distributions in Europe and have similar niches in bogs. <i>Sphagnum</i> species of bogs are closely related, with a large degree of microhabitat niche overlap between many species that can be functionally very similar. Despite this, ecologically similar species do have different distributional ranges along climatic gradients that partly overlap. These gradients may favor particular <i>Sphagnum</i> traits, especially in relation to water economy, which can be hypothesized to drive species divergence by character displacement.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We investigated traits relevant for water economy of two parapatric bryophytes (<i>Sphagnum cuspidatum</i> and <i>S. lindbergii</i>) across the border of their distributional limits. We included both shoot traits and canopy traits, i.e., collective traits of the moss surface, quantified by photogrammetry.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The two species are ecologically similar and occur at similar positions along the hydrological gradient in bogs. The biggest differences between the species were expressed in the variations of their canopy surfaces, particularly surface roughness and in the responses of important traits such as capitulum mass to climate. We did not find support for character displacement, because traits were not more dissimilar in sympatric than in allopatric populations.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results suggest that parapatry within <i>Sphagnum</i> can be understood from just a few climatic variables and that climatic factors are stronger drivers than competition behind trait variation within these species of <i>Sphagnum</i>.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140955885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of local habitat and spatial connectivity on urban seed predation","authors":"Álvaro Gaytán,&nbsp;Laura J. A. van Dijk,&nbsp;Maria Faticov,&nbsp;Anna E. Barr,&nbsp;Ayco J. M. Tack","doi":"10.1002/ajb2.16333","DOIUrl":"10.1002/ajb2.16333","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>During the last centuries, the area covered by urban landscapes is increasing all over the world. Urbanization can change local habitats and decrease connectivity among these habitats, with important consequences for species interactions. While several studies have found a major imprint of urbanization on plant–insect interactions, the effects of urbanization on seed predation remain largely unexplored.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We investigated the relative impact of sunlight exposure, leaf litter, and spatial connectivity on predation by moth and weevil larvae on acorns of the pedunculate oak across an urban landscape during 2018 and 2020. We also examined whether infestations by moths and weevils were independent of each other.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>While seed predation varied strongly among trees, seed predation was not related to differences in sunlight exposure, leaf litter, or spatial connectivity. Seed predation by moths and weevils was negatively correlated at the level of individual acorns in 2018, but positively correlated at the acorn and the tree level in 2020.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our study sets the baseline expectation that urban seed predators are unaffected by differences in sunlight exposure, leaf litter, and spatial connectivity. Overall, our findings suggest that the impact of local and spatial factors on insects within an urban context may depend on the species guild. Understanding the impact of local and spatial factors on biodiversity, food web structure, and ecosystem functioning can provide valuable insights for urban planning and management strategies aimed at promoting urban insect diversity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16333","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140955804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific plant-soil feedback in four tropical tree species is inconsistent in a field experiment.","authors":"Jenalle L Eck, Lourdes Hernández Hassan, Liza S Comita","doi":"10.1002/ajb2.16331","DOIUrl":"https://doi.org/10.1002/ajb2.16331","url":null,"abstract":"<p><strong>Premise: </strong>Soil microbes can influence patterns of diversity in plant communities via plant-soil feedbacks. Intraspecific plant-soil feedbacks occur when plant genotype leads to variations in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near nonmaternal conspecific plants. How consistently such intraspecific plant-soil feedbacks occur in natural plant communities is unclear, especially in variable field conditions.</p><p><strong>Methods: </strong>In an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama, seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post-transplant) and at the end of the experiment (~7 months post-transplant).</p><p><strong>Results: </strong>Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the four species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while seedling survival of Ormosia macrocalyx was higher under other conspecific trees. However, these differences were gone by the end of the experiment.</p><p><strong>Conclusions: </strong>Our results suggest that intraspecific plant-soil feedbacks may not be consistent in the field for tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant-soil feedbacks in plant communities.</p>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140943610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How and why do species break a developmental trade-off? Elucidating the association of trichomes and stomata across species","authors":"Alec S. Baird,&nbsp;Camila D. Medeiros,&nbsp;Marissa A. Caringella,&nbsp;Julia Bowers,&nbsp;Michelle Hii,&nbsp;John Liang,&nbsp;Joshua Matsuda,&nbsp;Kirthana Pisipati,&nbsp;Caroline Pohl,&nbsp;Benjamin Simon,&nbsp;Silvard Tagaryan,&nbsp;Thomas N. Buckley,&nbsp;Lawren Sack","doi":"10.1002/ajb2.16328","DOIUrl":"10.1002/ajb2.16328","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Previous studies have suggested a trade-off between trichome density (<i>D</i>_t) and stomatal density (<i>D</i>_s) due to shared cell precursors. We clarified how, when, and why this developmental trade-off may be overcome across species.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We derived equations to determine the developmental basis for <i>D</i>_t and <i>D</i>_s in trichome and stomatal indices (<i>i</i>_t and <i>i</i>_s) and the sizes of epidermal pavement cells (<i>e</i>), trichome bases (<i>t</i>), and stomata (<i>s</i>) and quantified the importance of these determinants of <i>D</i>_t and <i>D</i>_s for 78 California species. We compiled 17 previous studies of <i>D</i>_t–<i>D</i>_s relationships to determine the commonness of <i>D</i>_t–<i>D</i>_s associations. We modeled the consequences of different <i>D</i>_t–<i>D</i>_s associations for plant carbon balance.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Our analyses showed that higher <i>D</i>_t was determined by higher <i>i</i>_t and lower <i>e</i>, and higher <i>D</i>_s by higher <i>i</i>_s and lower <i>e</i>. Across California species, positive <i>D</i>_t–<i>D</i>_s coordination arose due to <i>i</i>_t–<i>i</i>_s coordination and impacts of the variation in <i>e</i>. A <i>D</i>_t–<i>D</i>_s trade-off was found in only 30% of studies. Heuristic modeling showed that species sets would have the highest carbon balance with a positive or negative relationship or decoupling of <i>D</i>_t and <i>D</i>_s, depending on environmental conditions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Shared precursor cells of trichomes and stomata do not limit higher numbers of both cell types or drive a general <i>D</i>_t–<i>D</i>_s trade-off across species. This developmental flexibility across diverse species enables different <i>D</i>_t–<i>D</i>_s associations according to environmental pressures. Developmental trait analysis can clarify how contrasting trait associations would arise within and across species.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16328","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140896997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards a species-level phylogeny for Neotropical Myrtaceae: Notes on topology and resources for future studies","authors":"The Neotropical Myrtaceae Working Group,&nbsp;Vanessa G. Staggemeier,&nbsp;Bruno Amorim,&nbsp;Mariana Bünger,&nbsp;Itayguara R. Costa,&nbsp;Jair Eustáquio Quintino de Faria,&nbsp;Jonathan Flickinger,&nbsp;Augusto Giaretta,&nbsp;Marcelo T. Kubo,&nbsp;Duane Fernandes Lima,&nbsp;Leidiana Lima dos Santos,&nbsp;Ana Raquel Lourenço,&nbsp;Eve Lucas,&nbsp;Fiorella Fernanda Mazine,&nbsp;José Murillo-A,&nbsp;Marla Ibrahim Uehbe de Oliveira,&nbsp;Carlos Parra-O,&nbsp;Carolyn E. B. Proença,&nbsp;Marcelo Reginato,&nbsp;Priscila Oliveira Rosa,&nbsp;Matheus Fortes Santos,&nbsp;Aline Stadnik,&nbsp;Amélia Carlos Tuler,&nbsp;Karinne Sampaio Valdemarin,&nbsp;Thais Vasconcelos","doi":"10.1002/ajb2.16330","DOIUrl":"10.1002/ajb2.16330","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Increasingly complete phylogenies underpin studies in systematics, ecology, and evolution. Myrteae (Myrtaceae), with ~2700 species, is a key component of the exceptionally diverse Neotropical flora, but given its complicated taxonomy, automated assembling of molecular supermatrices from public databases often lead to unreliable topologies due to poor species identification.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Here, we build a taxonomically verified molecular supermatrix of Neotropical Myrteae by assembling 3909 published and 1004 unpublished sequences from two nuclear and seven plastid molecular markers. We infer a time-calibrated phylogenetic tree that covers 712 species of Myrteae (~28% of the total diversity in the clade) and evaluate geographic and taxonomic gaps in sampling.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The tree inferred from the fully concatenated matrix mostly reflects the topology of the plastid data set and there is a moderate to strong incongruence between trees inferred from nuclear and plastid partitions. Large, species-rich genera are still the poorest sampled within the group. Eastern South America is the best-represented area in proportion to its species diversity, while Western Amazon, Mesoamerica, and the Caribbean are the least represented.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>We provide a time-calibrated tree that can be more reliably used to address finer-scale eco-evolutionary questions that involve this group in the Neotropics. Gaps to be filled by future studies include improving representation of taxa and areas that remain poorly sampled, investigating causes of conflict between nuclear and plastid partitions, and the role of hybridization and incomplete lineage sorting in relationships that are poorly supported.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16330","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140896160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intraspecific divergence in a coastal plant, Euphorbia jolkinii, at a major biogeographic boundary in East Asia","authors":"Hiroyuki Iwata,&nbsp;Takuro Ito,&nbsp;Jong-Soo Park,&nbsp;Goro Kokubugata,&nbsp;Akihiro Kakezawa,&nbsp;Takahide Kurosawa,&nbsp;Akihiro Nishimura,&nbsp;Hiroshi Noda,&nbsp;Koji Takayama","doi":"10.1002/ajb2.16327","DOIUrl":"10.1002/ajb2.16327","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Quaternary climatic fluctuations and long-distance seed dispersal across the sea are critical factors affecting the distribution of coastal plants, but the spatiotemporal nature of population expansion and distribution change of East Asian coastal plants during this period are rarely examined. To explore this process, we investigated the genome-wide phylogenetic patterns of <i>Euphorbia jolkinii</i> Boiss. (Euphorbiaceae), which grows widely on littoral areas of Japan, Korea, and Taiwan.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We used plastome sequences and genome-wide single nucleotide polymorphisms in samples across the species range to reveal phylogeographic patterns and spatiotemporal distributional changes. We conducted ecological niche modeling for the present and the last glacial maximum (LGM).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Genetic differentiation was observed between the northern and southern populations of <i>E. jolkinii</i>, separated by the major biogeographic boundary, the Tokara Gap. These two groups of populations differentiated during the glacial period and subsequently intermingled in the intermorainic areas of the central Ryukyu Islands after the LGM. Ecological niche models suggested that the potential range of <i>E. jolkinii</i> was restricted to southern Kyushu; however, it was widespread in the southern Ryukyu Islands and Taiwan during the LGM.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study provides evidence of genetic differentiation among coastal plant populations separated by the prominent biogeographical boundary. Although coastal plants are typically expected to maintain population connectivity through sea-drifted seed dispersal, our findings suggest that genetic differences may arise because of a combination of limited gene flow and changes in climate during the glacial period.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140896040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harmful self-pollination drives gynodioecy in European chestnut, a self-incompatible tree","authors":"Clément Larue,&nbsp;Rémy J. Petit","doi":"10.1002/ajb2.16329","DOIUrl":"10.1002/ajb2.16329","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Premise</h3>\u0000 \u0000 <p>Gynodioecy is a rare sexual system in which two genders (<i>sensu</i> Lloyd, 1980), cosexuals and females, coexist. To survive, female plants must compensate for their lack of siring capacity and male attractiveness. In European chestnut (<i>Castanea sativa</i>), an outcrossing tree, self-pollination reduces fruit set in cosexual individuals because of late-acting self-incompatibility and early inbreeding depression. Could this negative sexual interaction explain the presence of females in this species?</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>We studied gender variation in wild populations of European chestnut. In addition, we compared fruit set (the proportion of flowers giving fruits) and other key female fitness components as well as reproductive allocation between genders. We then performed emasculation experiments in cosexual trees, by removing nectar-producing fertile male inflorescences. We also removed sterile but nectar-producing male inflorescences from female trees, as a control.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>We found a highly variable proportion of male-sterile individuals in the wild in European chestnut. In the experimental plot, trees from each gender had similar size, flower density, and burr set, but different fruit set. Removing nectar-producing male inflorescences from branches or entire trees increased fruit set in cosexual but not in female trees.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These results show that self-pollination impairs fruit set in cosexual trees. Female trees avoid these problems as they do not produce pollen but continue to attract pollinators thanks to their rewarding male-sterile inflorescences, resulting in a much higher fruit set than in cosexuals. This demonstrates that even outcrossed plants can benefit from the cessation of self-pollination, to the point that unisexuality can evolve.</p>\u0000 </section>\u0000 </div>","PeriodicalId":7691,"journal":{"name":"American Journal of Botany","volume":null,"pages":null},"PeriodicalIF":3.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajb2.16329","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140849354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}